Electric cable system



Aug. 14, 1945.

F. J. WHITE ELECTRIC CABLE SYSTEM Filed Nov. 25, 1942 INVENTOR BY flQ ATTORNEY Patented Aug. 14, 1945 2,382,120 ELECTRIC CABLE SYSTEIH Francis J. White, Brooklyn, N. Y., assignor to The Okonite-Callender Cable Company, Incorporated, Paterson, N. J

Jersey a corporation of New Application November 25, 1942, Serial No. 466,8 80 1 Claims (Cl. 174-44) My invention is directed to an improvement in electric cable systems whereby any fire. that might be caused, for example, by a short circuit in the cable itself or by outside sources will quickly be extinguished.

More specifically I provide a tube in proximity to the cable to be protected, and in eflect constituting a part of the cable system, this tube being filled with fire extinguishing fluid. The tube is ruptured under conditions which would produce a fire in the system and discharges its contents upon the flre to extinguish the same.

In the accompanying drawing:

Fig. l is a perspective view in part section showing my invention incorporated in a cable duct system;

Fig. 2 shows in part section another embodiment of my invention incorporated in a cable duct system; and

Fig. 3 is a cross section of an embodiment of my invention as applied to a cable system of the type where the cableconductors are submerged in oil or gas in a pipe line.

Referring to the drawing in detail and first of all to the embodiment of my invention illustrated in Fig. 1: 2 designates a duct system of usual construction, the ducts 4 containing electrically insulated wires or cables 8, which are insulated with any suitable type of commercial insulation.

As above pointed out, .my invention has for an object to protect such a system against fire which may be caused by a short circuit in the system, or which may originate outside the cable system but in its immediate vicinity. Accordingly I install a tube 8 in one or more of the ducts 4, the tube, it being understood, preferably extending the entire length of the duct. This tube -8 contains a suitable fire extinguishing fluid which may be either a liquid or a gas. Carbon tetrachloride is an example of a suitable material. The tube 8 may be made of various materials, as, for example, of a low melting point metal, or of a material the resistance to bursting of which is comparatively low, the intent being that in the event of a fire starting from any cause in the cable system or starting in the immediate vicinity of the system the tube I will either melt down from the heat generated or rupture due to the expansion of its contained flre extinguishing fluid, thereby releasing the fluid and discharging the same upon the fire to extinguish the same. It will be appreciated, of course, that in the event of a fire the walls of the ducts will be disintegrated sufllciently to enable the released extinguishing fluid to reach the fire.

In the embodiment of my invention as illustrated in Fig. 2, I again show a duct system 2, in which the tube 8 lies in the same duct as the the event of fire to release cable 6 to be protected, instead of in a separate duct as in Fig. l. The tube 8 and its contents may be identical with Fig. 1 and, as above explained, the tube will rupture or disintegrate m the extinguishing fluid.

It will be understood that in both embodiments of my invention so far described the tube 8 can be drawn into its duct when the cables are being drawn in. It will be appreciated also that several tubes may be employed, if desired, instead of the single tube illustrated.

Fig. 3 illustrates still another embodiment of my invention as applied to a diilerent type of cable installation. The cable here illustrated is of that type wherein the insulated conductors 6 are loosely enclosed in a pipe line It filled with a liquid or a gaseous insulating fluid- [2 which is maintained at superatmospheric pressure. In this type of installation I place the tube 8, containing a fire extinguishing fluid, within the pipe line, and

maintain the pressure within the tube 8 the same or approximately the same as the pressure in the pipe line. Should the pipe line H! be ruptured from any cause so as to release the insulatins fluid and hence lower the pressure in the pipe line, the initial balance between the internal and external pressures on the tube 8 will be upset and the tube 8 will burst from internal pressure thereby to release its contents. If desired, the tube 8 or an additional tube could be installed along the exterior of the pipe line It, comparable to the showing in Fig. 2 where mechanical damage or heat would cause its rupture and allow its contents to flood the immediate vicinity.

It will be appreciated, 0! course, that in the type of system illustrated in Fig. 3 the tube 8 may be drawn into the pipe line Ill when the insulated conductors are being drawn in.

It is to be understood that changes may be v made in the details of construction and arrans' ment or parts herein shown and described within the purview of my invention.

What I claim is:

An electric cable system comprising in combination a pipe line, a conductor insulated with fluid pervious material loosely enclosed in said pipe line, an insulating fluid under superatmospheric pressure within the pipe line in which the insulated conductor is submerged. a tube within the pipe line extending the length thereof and submerged in said insulating fluid and containing a fire extinguishing fluid, said flre extinguishing fluid being under sufficiently high pressure to effect rupture of the tube and escape oi the the extinguishing fluid therefrom into the surrounding insulating fluid upon the rupture-oi said pipe line and resultant drop in the pressure of the insulating fluid.

FRANCIS J. WHITE. 

